React Component Testing
What you'll learn​
- How to set up component tests in React
- How to use Cypress with different React frameworks and bundlers
Framework Support​
Cypress Component Testing currently supports React 16+ with the following frameworks:
Tutorial​
Visit the Getting Started Guide for a step-by-step tutorial on adding component testing to any project and how to write your first tests.
Installation​
To get up and running with Cypress Component Testing in React, install Cypress into your project:
- npm
- yarn
- pnpm
npm install cypress --save-dev
yarn add cypress --dev
pnpm add --save-dev cypress
Open Cypress:
- npm
- yarn
- pnpm
npx cypress open
yarn cypress open
pnpm cypress open
The Cypress Launchpad will guide you through configuring your project.
For a step-by-step guide on how to create a component test, refer to the Getting Started guide.
For usage and examples, visit the React Examples guide.
Framework Configuration​
Cypress Component Testing works out of the box with Create React App, Next.js, Vite, and a custom Webpack config. Cypress will automatically detect one of these frameworks during setup and configure them properly. The examples below are for reference purposes.
Create React App (CRA)​
Cypress Component Testing works with CRA 4+.
CRA Configuration​
- cypress.config.js
- cypress.config.ts
const { defineConfig } = require('cypress')
module.exports = defineConfig({
component: {
devServer: {
framework: 'create-react-app',
bundler: 'webpack',
},
},
})
import { defineConfig } from 'cypress'
export default defineConfig({
component: {
devServer: {
framework: 'create-react-app',
bundler: 'webpack',
},
},
})
Sample Create React Apps​
Next.js​
Cypress Component Testing works with Next.js 11+.
Next.js Configuration​
- cypress.config.js
- cypress.config.ts
const { defineConfig } = require('cypress')
module.exports = defineConfig({
component: {
devServer: {
framework: 'next',
bundler: 'webpack',
},
},
})
import { defineConfig } from 'cypress'
export default defineConfig({
component: {
devServer: {
framework: 'next',
bundler: 'webpack',
},
},
})
Next.js Caveats​
There are some specific caveats to consider when testing Next.js Pages in component testing.
A page component could have additional logic in its getServerSideProps
or
getStaticProps
methods. These methods only run on the server, so they are not
available to run inside a component test. Trying to test a page in a component
test would result in the props being passed into the page to be undefined.
While you could pass in props directly to the page component in a component test, that would leave these server-side methods untested. However, an end-to-end test would execute and test a page entirely.
Because of this, we recommend using E2E Testing over Component Testing for Next.js pages and Component Testing for individual components in a Next.js app.
Sample Next.js Apps​
React with Vite​
Cypress Component Testing works with React apps that use Vite 2+ as the bundler.
Vite Configuration​
- cypress.config.js
- cypress.config.ts
const { defineConfig } = require('cypress')
const customViteConfig = require('./customConfig')
module.exports = defineConfig({
component: {
devServer: {
framework: 'react',
bundler: 'vite',
// optionally pass in vite config
viteConfig: customViteConfig,
// or a function - the result is merged with
// any `vite.config` file that is detected
viteConfig: async () => {
// ... do things ...
const modifiedConfig = await injectCustomConfig(baseConfig)
return modifiedConfig
},
},
},
})
import { defineConfig } from 'cypress'
import customViteConfig from './customConfig'
export default defineConfig({
component: {
devServer: {
framework: 'react',
bundler: 'vite',
// optionally pass in vite config
viteConfig: customViteConfig,
// or a function - the result is merged with
// any `vite.config` file that is detected
viteConfig: async () => {
// ... do things ...
const modifiedConfig = await injectCustomConfig(baseConfig)
return modifiedConfig
},
},
},
})
Sample React Vite Apps​
React with Webpack​
Cypress Component Testing works with React apps that use Webpack 4+ as the bundler.
Webpack Configuration​
- cypress.config.js
- cypress.config.ts
const { defineConfig } = require('cypress')
const webpackConfig = require('./webpack.config')
module.exports = defineConfig({
component: {
devServer: {
framework: 'react',
bundler: 'webpack',
// optionally pass in webpack config
webpackConfig,
// or a function - the result is merged with any
// webpack.config that is found
webpackConfig: async () => {
// ... do things ...
const modifiedConfig = await injectCustomConfig(baseConfig)
return modifiedConfig
},
},
},
})
import { defineConfig } from 'cypress'
import webpackConfig from './webpack.config'
export default defineConfig({
component: {
devServer: {
framework: 'react',
bundler: 'webpack',
// optionally pass in webpack config
webpackConfig,
// or a function - the result is merged with any
// webpack.config that is found
webpackConfig: async () => {
// ... do things ...
const modifiedConfig = await injectCustomConfig(baseConfig)
return modifiedConfig
},
},
},
})
If you don't provide a webpack config, Cypress will try to infer it. If Cypress
cannot do so, or you want to make modifications to your config, you can specify
it via the webpackConfig
option.